ES2872952T3 - Communication with short TTI - Google Patents

Abstract

A method for use in a wireless device in communication with a first cell to acquire system information, SI, from a second cell, the first cell can be operated to use two or more transmission time intervals, TTI, the method comprising: obtaining (812) a request to acquire the SI of the second cell; obtain (814) the SI of the second cell over a period of time, T0; determining (816) a TTI length used for wireless communication with the wireless device in the first cell; in response to receiving (818) downlink data from the first cell during time T0: when the determined TTI length is equal to a first TTI value, TTI1, transmit (820) a first minimum number, N1, of signals uplink feedback in the uplink of the first cell during T0; and when the determined TTI length is equal to a second TTI value, TTI2, transmitting (820) a second minimum number, N2, of uplink feedback signals on the uplink of the first cell during T0; where TTI1 is a shorter duration than TTI2 and N1 is greater than N2.

Description

DESCRIPTION

Communication with short TTI

Technical field

The various embodiments of the present description relate generally to wireless communications and more specifically to the performance of the serving cell for acquiring system information (SI) with a short transmission time interval (TTI).

Introduction

Document US 2016/262137 describes a method carried out in a wireless device located in a first cell operated by a network node of a wireless communication system. The method comprises acquiring (510) the system information of a second cell using at least one autonomous space over a period of time. The wireless device is configured with a flexible subframe allocation scheme in the first cell for at least a portion of the time period.

Document WO 2013/172757 describes a UE (30) configured in multicarrier with at least one secondary cell (SCelda) that can send feedback signals to the network when the measurement spaces are active, which prevents the UE (30) communicate in the primary cell (PCelda).

The Long-Term Evolution (LTE) Third Generation Partnership Project (3GPP) uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink, where each downlink symbol can be called OFDM symbol, and OFDM Broadcast Discrete Fourier Transform (DFT) on the uplink, where each uplink symbol can be referred to as a single carrier frequency division multiplexing (SC-FDMA) symbol. The LTE downlink basic physical resource comprises a time-frequency grid as illustrated in FIGURE 1.

FIGURE 1 illustrates an example downlink radio subframe. The horizontal axis represents time and the other axis represents frequency. Each resource element corresponds to an OFDM subcarrier during an OFDM symbol interval. In the time domain, LTE downlink transmissions can be organized into radio frames.

FIGURE 2 illustrates an example radio frame. Each radio frame is 10 ms and consists of ten subframes of equal size of length Tsubframe = 1 ms. For the normal cyclic prefix, a subframe consists of 14 OFDM symbols. The duration of each symbol is approximately 71.4 gs.

Users are assigned a specific number of subcarriers for a predetermined amount of time. These are known as physical resource blocks (PRBs). Therefore, PRBs have both a time and a frequency dimension. A resource block corresponds to an interval (0.5 ms) in the time domain and 12 contiguous subcarriers in the frequency domain. A pair of two adjacent resource blocks in the direction of time (1.0 ms) is known as a resource block pair. The time interval may be referred to as a transmission time interval (TTI).

Downlink transmissions are dynamically scheduled (i.e. in each subframe a base station transmits control information on which terminals the data is transmitted to and on which resource blocks the data is transmitted, for the current downlink subframe). Control signaling is normally transmitted in the first 1, 2, 3 or 4 OFDM symbols in each subframe and the number n = 1, 2, 3 or 4 is known as the Control Format Indicator (CFI) indicated by the channel Physical CFI (PCFICH) transmitted in the first symbol of the control region. The control region also contains physical downlink control channels (PDCCH) and possibly also physical HARQ indication channels (PHICH) carrying ACK / NACK for uplink transmission.

The downlink subframe also contains common reference symbols (CRS), which are known to the receiver and are used for coherent demodulation of, for example, control information. FIGURE 1 illustrates a downlink system with CFI = 3 OFDM symbols as a control. In a Ver-8 TTI, one such part of the downlink transmission is called a TTI.

Packet data latency is one of the performance metrics that providers, carriers and also end users (through speed test applications) measure regularly. Latency measurements are performed at all phases of the life of a radio access network system, such as when a new version of software or system component is verified, when a system is deployed, and when the system is in operation. commercial.

The shorter latency than previous generations of 3GPP Radio Access Technologies (RAT) is a performance metric that guided the design of LTE. End users recognize that LTE provides faster Internet access and lower data latencies than previous generations of mobile radio technologies.

Packet data latency is important not only for the perceived responsiveness of the system, but it is also a parameter that indirectly influences system performance. HTTP / TCP is the dominant application and transport layer protocol suite in use on the Internet today. According to the HTTP file (see httparchive.org under trends), the typical size of HTTP-based transactions over the Internet is in the range of a few tens of Kbytes to 1 Mbyte. In this size range, the TCP slow start period is a significant part of the total transport period of the packet stream. During slow TCP startup, performance is latency-limited. Therefore, the improved latency can improve average throughput for these types of TCP-based data transactions.

Latency reductions can improve the efficiency of radio resources. Lower packet data latency can increase the number of possible transmissions within a certain delay limit; therefore, higher Block Error Rate (BLER) targets can be used for data transmissions, freeing up radio resources and potentially improving system capacity.

One area to address when it comes to packet latency reductions is reducing data transport time and control signaling by modifying the TTT length. In LTE version 8, a TTI corresponds to a 1 millisecond long subframe (SF). One of these 1 ms TTIs is constructed using 14 OFDM or SC-FDMA symbols in the case of a normal cyclic prefix and 12 OFDM or SC-FDMA symbols in the case of an extended cyclic prefix. LTE version 13 can specify TTI transmissions that are much shorter than LTE version 8 TTIs. The shorter TTIs can be of any length in time and comprise resources in various OFDM or SC-FDMA symbols within a 1 ms SF. As an example, the duration of the short TTI can be 0.5 ms (ie seven OFDM or SC-FDMA symbols for the normal cyclic prefix case). As another example, the duration of the short TTI can be 2 symbols.

As seen in FIGURE 1, the TTI length consists of 14 OFDM symbols. In case of shortened TTI, the length of TTI can be reduced to 2 OFDM symbols, 4 OFDM symbols or 7 OFDM symbols. These are denoted as: 2-OS sTTI, 4-OS sTTI, 7-OS sTTI, respectively. The OFDM symbol here can also be the SC-FDMA symbol or any type of symbol.

The abbreviated TTI can be used in different values in different directions, such as downlink and uplink. For example: a downlink can use 2-OS sTTI, while the uplink can use 4-OS sTTI in the same cell.

Different frame structures, such as FS1, FS2, and FS3, can use different length sTTIs. The time domain structure in FIGURE 2 is related to FS1. 2 OS, 4 OS and 7 OS TTI can be used for FS1. For FS2 that is used for TDD, 7-OS sTTI is one of the abbreviated TTI modes. Some examples of TTI durations are illustrated in FIGURES 3-6.

For example, certain networks may use a 7 symbol TTI on the downlink. FIGURE 3 illustrates an example of a 7 symbol TTI. For the 7 symbol TTI, the sTTI structure of FIGURE 3 is uplink compatible.

Specific networks may use a 4 symbol TTI on the downlink. FIGURE 4 illustrates an example of a 4 symbol TTI. If 4 symbol uplink sTTI is supported, the sTTI structure of FIGURE 4 is adopted.

FIGURE 5 illustrates examples of short TTIs for uplink. The example in FIGURE 5 shows various lengths of TTIs. The 2 OS STTI can have one of the two options illustrated.

The following characteristics apply to uplink STTI. Three different TTI lengths can be used for the uplink. Of the three, different patterns are possible for 2-OS TTIs. A fast uplink grant may include a dynamic indication of the TTI length and / or a dynamic indication of the position of a demodulation reference signal (DMRS). For some TTI patterns, it is possible to share the DMRS between UEs. For some UEs, this also means that the UE will send the DMRS for two TTIs when the UE is scheduled through neighboring TTIs.

A wireless device, such as a UE, can acquire system information (SI) using autonomous spaces. In E-UTRAN, the serving cell can request the UE to acquire the global cell identifier (CGI) of a cell, which uniquely identifies the cell. To acquire the CGI of the cell, the UE reads at least part of the system information (SI), including the master information block (MIB) and the relevant system information block (SIB) of that cell, as described later. The reading of the SI for the acquisition of the CGI is carried out during the measurement spaces that are created autonomously by the UE (that is, the spaces are not configured by the network node, but rather the UE lets them believe). The CGI or the SI or the ECGI is also considered a UE measurement, which the UE can also report to the network node.

In LTE, a UE reads the E-UTRAN cell MIB and SIB1 of the target cell to acquire its CGI (ie, the ECGI when the target cell is intra- or inter-frequency E-UTRAN). The MIB includes a limited number of essential and frequently transmitted parameters that are necessary to acquire other information from the cell, and is transmitted at the BCH. Specifically, the following information is currently included in the MIB: the downlink bandwidth, the PHICH configuration, and the system frame number (SFN).

The MIB is transmitted periodically with a periodicity of 40 ms and the repetitions are made within 40 ms. The first transmission of the MIB is scheduled in subframe # 0 of radio frames for which SFN mod 4 = 0, and repeats are scheduled in subframe # 0 of all other radio frames.

In LTE, SIB1 contains at least the following information: PLMN identity, cell identity, CSG identity and indication, frequency band indicator, SI window length, scheduling information for other SIBs, etc. The SIB1 LTE, as well as other SIB messages, is transmitted on a physical channel, such as the PDSCH. FIGURE 6 shows an example of MIB and SIB1 acquisition through the use of autonomous spaces created by the UE.

FIGURE 6 illustrates the acquisition of the MIB and SIB1 FDD E-UTRA. The SIB1 is transmitted with a periodicity of 80 ms and the repetitions are carried out within 80 ms. The first transmission of the TipoBloqueInformacionSistema1 is programmed in subframe # 5 of the radio frames for which SFN mod 8 = 0, and the repetitions are programmed in subframe # 5 of all other radio frames for which SFN mod 2 = 0.

One problem with the current specs is that the UE supports only one TTI (i.e. 1ms). The UE requirements for the acquisition of the SI of the target cell are defined based on only 1 ms of TTI. The requirements are defined in terms of SI acquisition delay and number of ACK / NACKs transmitted by the UE in the serving cell. This is to ensure that the UE does not create unnecessary autonomous spaces when it acquires the SI of the target cell. The UE that supports shorter TTIs can lead to significant performance degradation if the same requirements are applied.

Compendium

The embodiments described herein include various methods at the UE and the network node. In general, a method in a UE can comprise the following steps:

Step-1: Get a request to acquire a system information (SI) from a second cell (cell2);

Step-2: Acquire the SI of cell2 in autonomous spaces during a period of time (T0);

Step-3: Transmit a minimum first number (N1) of uplink feedback signals in a first cell (cell1) in response to receiving downlink data in cell1 if the UE uses a first TTI (TTI1) in cell1 during T0, and a second minimum number (N2) of uplink feedback signals in cell1 in response to receiving downlink data in cell1 if the UE uses a second TTI (TTI2) in cell1 during T0;

Step-4: Use the results of the acquired SI from cell2 to perform one or more operational tasks (for example, determine the global identity of the cell (CGI), transmit the results to another node, switch cells, etc.) .

In general, a method on a network node can comprise the following steps:

Step-1: Configure a UE to acquire a system information (SI) from a second cell (cell2) using autonomous spaces during the time period (T0);

Step-2: Determine a first minimum number (N1) of uplink feedback signals that the UE can transmit in a first cell (cell1) in response to receiving downlink data in cell1 if the UE uses a first TTI (TTI1) in cell1 during T0, or a second minimum number (N2) of uplink feedback signals that the UE can transmit in cell1 in response to receiving downlink data in cell1 if the UE uses a second TTI (TTI2) in cell1 during T0;

Step-3: Transmit downlink data to UE during T0 in cell1;.

Step-4: Receive N1 uplink feedback signals from the UE in cell1 in response to transmitting downlink data in cell1 if the UE uses TTI1 in cell1 during T0, or N2 uplink feedback from the UE in cell1 in response to downlink data transmission in cell1 if the UE uses TTI2 in cell1 during T0;

Step 5: Use the results of the number of uplink feedback signals received from the UE in cell1 and / or the results of the SI acquired from cell1 to perform one or more operational tasks.

According to some embodiments, a method for using in a wireless device in communication with a first cell to acquire system information (SI) from a second cell, the first cell can be operated to use two or more transmission time intervals (TTI) , understanding the method: obtain an application to acquire the SI from the second cell; obtain the SI of the second cell during a period of time (T0); and determining a TTI length used for wireless communication with the wireless device in the first cell. In response to receiving downlink data from the first cell during time T0: when the determined TTI length is equal to a first TTI value (TTI1), the method further comprises transmitting a first minimum number (N1) of signal signals. uplink feedback on the uplink of the first cell during T0; and when the determined TTI length is equal to a second TTI value (TTI2), the method further comprises transmitting a second minimum number (N2) of uplink feedback signals in the uplink of the first cell during T0. TTI1 is a shorter duration than TTI2 and N1 is greater than N2.

In particular embodiments, determining the TTI length comprises determining one of an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. Obtaining the SI of the second cell may include measuring signals in various measurement spaces. The method may further comprise, when the wireless device is unable to transmit the N1 or N2 uplink feedback signals during T0, reducing the number of measurement spaces or increasing T0.

In specific embodiments, the measurement spaces comprise autonomous spaces created by the wireless device in at least the first cell during time T0. For example, TTI1 can be less than 1 ms and N1 greater than 60.

In particular embodiments, N1 and N2 depend on a time division duplex (TDD) uplink / downlink subframe configuration of the first cell. The uplink feedback signals may include hybrid automatic repeat request (HARQ) and negative acknowledgment (NACK) acknowledgment (ACK) signals.

According to some embodiments, a wireless device is in communication with a first cell to acquire the SI of a second cell. The first cell can be operated to use two or more TTIs. The wireless device comprises processing circuitry that can be operated to: obtain a request to acquire the SI of the second cell; obtain the SI of the second cell during a period of time (T0); and determining a TTI length used for wireless communication with the wireless device in the first cell. In response to receiving downlink data from the first cell during time T0: when the determined TTI length equals a first TTI value (TTI1), the processing circuitry can be operated to transmit a first number ( N1) minimum uplink feedback signals in the uplink of the first cell during T0; and when the determined TTI length is equal to a second TTI value (TTI2), the processing circuitry can be operated to transmit a second minimum number (N2) of uplink feedback signals in the uplink of the first cell. during T0. TTI1 is a shorter duration than TTI2 and N1 is greater than N2.

In particular embodiments, the processing circuitry may function to determine the TTI length by determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. The processing circuitry can be operated to obtain the SI of the second cell by measuring signals in various measurement spaces. The processing circuitry can further be operated to, when the wireless device cannot transmit the N1 or N2 uplink feedback signals during T0, reduce the number of measurement spaces or increase T0.

In specific embodiments, the measurement spaces comprise autonomous spaces created by the wireless device in at least the first cell during time T0. For example, TTI1 can be less than 1 ms and N1 greater than 60.

In particular embodiments, N1 and N2 depend on an uplink / downlink TDD subframe configuration of the first cell. The uplink feedback signals may include HARQ ACK / NACK signals.

According to some embodiments, a method for using in a network node of a first cell to configure a wireless device to acquire the SI of a second cell, the first cell can be operated to use two or more TTIs, the method comprises: setting the wireless device to acquire the SI of the second cell during a period of time (T0); determining a TTI length used for wireless communication with the wireless device in the first cell; and transmitting a continuous allocation of downlink data to the wireless device during time T0. When the determined TTI length equals a first TTI value (TTI1), the method further comprises receiving a first minimum number (N1) of uplink feedback signals from the wireless device during T0; and when the determined TTI length is equal to a second TTI value (TTI2), the method further comprises receiving a second minimum number (N2) of uplink feedback signals from the wireless device during T0. TTI1 comprises a shorter duration than TTI2 and N1 is greater than N2.

In particular embodiments, determining the TTI length comprises determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. On Some embodiments, when the network node does not receive N1 or N2 uplink feedback signals during T0, the method includes increasing T0.

For example, TTI1 is less than 1 ms and N1 is greater than 60.

In particular embodiments, N1 and N2 depend on an uplink / downlink TDD subframe configuration of the first cell.

According to some embodiments, a network node of a first cell is capable of configuring a wireless device for the SI of a second cell. The first cell can be operated to use two or more TTIs. The network node comprises processing circuitry that can be operated to: configure the wireless device to acquire the SI of the second cell over a period of time (T0); determining a TTI length used for wireless communication with the wireless device in the first cell; and transmitting a continuous allocation of downlink data to the wireless device during time T0. When the determined TTI length equals a first TTI value (TTI1), the processing circuitry can be operated to receive a first minimum number (N1) of uplink feedback signals from the wireless device during T0; and when the determined TTI length is equal to a second TTI value (TTI2), to receive a second minimum number (N2) of uplink feedback signals from the wireless device during T0. TTI1 comprises a shorter duration than TTI2 and N1 is greater than N2.

In particular embodiments, the processor can be operated to determine the TTI length by determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. The processor can be further operated to, when the network node does not receive N1 or N2 uplink feedback signals during T0, to increase T0.

For example, TTI1 is less than 1 ms and N1 is greater than 60.

In particular embodiments, N1 and N2 depend on an uplink / downlink TDD subframe configuration of the first cell. The uplink feedback signals may include HARQ ACK / NACK signals.

Certain embodiments of the present disclosure may provide one or more technical advantages. For example, a particular advantage of some embodiments is that the behavior of the UE with respect to the performance of the serving cell when acquiring the SI of a target cell is well defined. Another advantage is that the performance of scheduling the data to the UE in the serving cell is improved. This is because scheduling grants can be used more efficiently. Furthermore, the performance of the SI acquisition can at least be maintained or even improved even if the UE uses different TTIs in the uplink and the downlink of its serving cell. Certain embodiments may have none, some, or all of the listed benefits.

Brief description of the drawings

For a more complete understanding of the embodiments and their features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 illustrates an example downlink radio subframe;

FIGURE 2 illustrates an example radio frame;

FIGURE 3 illustrates an example 7 symbol TTI;

FIGURE 4 illustrates an example 4 symbol TTI;

FIGURE 5 illustrates examples of short TTI for uplink;

FIGURE 6 illustrates MIB and SIB1 FDD E-UTRA acquisition;

FIGURE 7 illustrates an example of a wireless network, according to a specific embodiment;

FIGURE 8 is a flow chart of an example method in a wireless device, according to some embodiments;

FIGURE 9 illustrates an example of HARQ feedback for the downlink / uplink configuration for 4th / 4th and 7th / 7th, according to some embodiments;

FIGURE 10 illustrates an example of HARQ feedback for the downlink / uplink configuration for 2nd / 2nd and 2nd / 1ms, according to some embodiments;

FIGURE 11 is a flow chart of an example method in a network node, according to some embodiments;

FIGURE 12A is a block diagram illustrating an example embodiment of a wireless device;

FIGURE 12B is a block diagram illustrating example components of a wireless device; FIGURE 13A is a block diagram illustrating an example embodiment of a network node; and

FIGURE 13B is a block diagram illustrating example components of a network node.

Detailed description

For the Long Term Evolution (LTE) of the Third Generation Partnership Project (3GPP), the latency of the data packets is important not only for the perceived responsiveness of the system, but it is also a parameter that indirectly influences the system performance. Latency reductions can improve the efficiency of radio resources. One aspect of reducing packet latency is reducing data transport time and control signaling by modifying the length of the transmission time interval (TTI). In earlier versions of LTE, a TTI corresponds to a 1 millisecond long subframe (SF). Newer versions of LTE can specify TTI transmissions of less than 1 millisecond. For example, the duration of the short TTI may be 0.5 ms (i.e. seven orthogonal frequency division multiplexing (OFDM) or single carrier frequency division multiplexing (SC-FDMA) symbols for the case with normal cyclic prefix). As another example, the duration of the short TTI can be 2 symbols or 4 symbols.

A wireless device, such as a user equipment (UE), can acquire system information (SI) using autonomous spaces. In E-UTRAN, the serving cell can request the UE to acquire the global cell identifier (CGI) of a cell, which uniquely identifies the cell. To acquire the CGI of the cell, the UE reads at least part of the system information (SI), including the master information block (MIB) and the relevant system information block (SIB) of that cell. The reading of the SI for the acquisition of the CGI is carried out during the measurement spaces that are created autonomously by the UE (that is, the spaces are not configured by the network node, but rather allows the UE to believe).

One problem with current LTE specifications is that the UE supports only one TTI (i.e. 1ms). The UE requirements for the acquisition of the target cell SI are defined based on only 1 ms of TTI. The requirements are defined in terms of the acquisition delay of the SI and number of ACK / NACKs transmitted by the UE in the serving cell. This is to ensure that the UE does not create unnecessary autonomous spaces when it acquires the SI of the target cell. The shorter TTI-supporting UE can lead to significant performance degradation if the same requirements are applied.

Concrete realizations obviate the problems described above. The ACK requirements to read the CGI were obtained assuming a TTI duration of 1 ms for both the uplink and the downlink. When using a shorter TTI, a higher number of transmitted ACK / NACK is expected. Specific embodiments include a minimum number of uplink acknowledgments based on a TTI duration.

Some embodiments refer to the term "node". An example of a node can be a network node, which can be a more general term and can correspond to any type of radio network node or any network node that communicates with a UE and / or another network node. Examples of network nodes include NodeB, base station (BS), multi-standard radio radio (MSR) node such as Bs MSR, eNodeB, gNodeB. MeNB, SeNB, Network Controller, Radio Network Controller (RNC), Base Station Controller (BSC), Relay, Donor Node Control Relay, Base Transceiver Station (BTS), Access Point (AP), Access Points transmission, transmission nodes, RRU, RRH, nodes in the distributed antenna system (DAS), core network node (for example, MSC, MME, etc.), O&M, OSS, SON, positioning node (for example , E-SMLC), MDT, etc.

Some embodiments refer to generic terminology such as "radio network node" or simply "network node (NW node)", which can be any type of network node, such as a base station, radio base station, base transceiver station. , Base Station Controller, Network Controller, Evolved Node B (eNB), Node B, Relay Node, Access Point, Radio Access Point, Remote Radio Unit (RRU), Remote Radio Head (RRH), etc.

Another example of a node can be a user equipment, which is a non-limiting term for user equipment (UE) and refers to any type of wireless device that communicates with a network node and / or another UE in a cellular or mobile communication system. Examples of UE are a target device, device-to-device UE (D2D), machine-type UE, or UE capable of machine-to-machine communication (M2M), PDA, tablet, mobile terminals, smartphone, laptop with embedded equipment (LEE), laptop-mounted equipment (LME), USB devices, etc.

The term Radio Access Technology, or RAT, can refer to any RAT, such as UTRA, E-UTRA, Narrowband Internet of Things (NB-IoT), WiFi, Bluetooth, Next Generation RAT (NR), 4G , 5G, etc. Either of the first and second nodes may be capable of supporting one or more RATs.

The term "signal" used here can be any physical signal or physical channel. Examples of physical signals are reference signals such as PSS, SSS, CRS, PRS, etc. The term "physical channel" (eg in the context of channel reception) used in this document is also called "channel". Examples of physical channels include the MIB, PBCH, NPBCH, PDCCH, PDSCH, sPUCCH, sPDSCH. sPUCCH. sPUSCH, MPDCCH, NPDCCH, NPDSCH, E-PDCCH, PUSCH, PUCCH, NPUSCH, etc.

The term "time resource" used herein can correspond to any type of physical resource or radio resource expressed in terms of duration. Examples of time resources include: symbol, timeslot, subframe, radio frame, TTI, interleaving time, etc.

The term "TTI" used herein can correspond to any period of time (T0) during which a physical channel can be encoded and optionally interleaved for transmission. The physical channel is decoded by the receiver during the same period of time (T0) during which it was encoded. The TTI can also be referred to interchangeably as short TTI (sTTI), transmission time, slot, sub slot, mini slot, short sub frame (SSF), mini sub frame, etc.

The term "radio measurement" used herein can refer to any measurement based on the reception of a radio signal or channel, for example, measurements based on power such as the intensity of the received signal (for example, RSRP or CSI-RSRP) or quality measurements (eg RSRQ, RS-SINR, SINR, Es / Iot, SNR); mobile identification; synchronization signal measurements; angle measurements such as angle of arrival (AOA); timing measurements such as Rx-Tx, RTT, RSTD, TOA, TDOA, timing advance; performance measurements; Channel quality measurements such as CSI, CQI, PMI, channel measurement (eg MIB, SIB, SI, CGI acquisitions, etc.). A measurement can be absolute, relative to a common reference, or to another measurement, compound measurement, and so on. A measurement can be on one link or more than one link (eg RSTD, timing advance, RTT, relative RSRP, etc.). Measurements can also be differentiated by purpose and can be performed for one or more purposes, eg for one or more of: RRM, MDT, SON, positioning, time control or timing advance, synchronization. In a non-limiting example, specific embodiments can be applied to any measurement as described above. In the present specification, the term "radio measurement" can be used in a broader sense, for example, receiving a channel (for example, receiving system information through a broadcast or multicast channel).

The term "requirements" used herein can include any type of UE requirements related to UE measurements, such as measurement requirements, RRM requirements, mobility requirements, positioning measurement requirements, etc. . Examples of UE requirements related to UE measurements are measurement time, measurement reporting time or delay, measurement accuracy (e.g. RSRP / RSRQ accuracy), number of cells to be measured during measurement. measurement time, etc. Examples of measurement time include L1 measurement period, cell identification time or cell search delay, CGI acquisition delay, etc. .

The term "interrupt" or "interrupt level" or "interrupt performance" used in this document can correspond to any type of signal interruption between a UE and its serving cell (eg, PCelda, SCeldas, PSCelda). The interruption can cause loss or degradation of the performance of the serving cell.

Interruptions can affect the performance of one or more service cells, for example, PCelda, PSCelda, SCelda, and so on. Loss in performance or service cell disruption can be expressed in terms of one or more metrics, which can be absolute or relative, such as error rate or packet loss or packet loss rate or number of lost packets or the packet drop rate or a reduction in the probability of detection or an increase in the probability of erroneous detection or even the probability of missing, deleted or lost packets. The outage level can be expressed in terms of one or more time resources that are interrupted (eg, 1 subframe, 5 subframe, 1 TTI, 2 TTI interrupt time, etc.).

A packet as used herein refers to any block of data, such as a transport block, sent over a radio interface on the uplink or downlink. The packet loss rate or the number of packets lost is usually estimated over a certain period of time (eg the measurement time of a radio measurement, a predefined time, etc.). In one example, the number of packets lost is expressed as the total number of ACK / NACKs lost in response to the continuous transmission of data to the UE from its serving cell over a certain period of time.

For example, the number of packets lost in LTE with a TTI of 1 ms will be 10 if the UE is unable to transmit 10 ACK / NACKs on the uplink in response to continuous downlink transmission for a period of 100 ms. In this example, the corresponding packet loss rate is 10% or 0.1. This can also be expressed as the probability that the ACK / NACK fraction transmitted on the uplink in response to continuous downlink transmission over a period is lost, dropped, or lost. It can also be expressed as a ratio of either or both of the following: (a) the number of lost ACK / NACKs transmitted by the UE in response to the continuous transmission of downlink data to the UE from its serving cell during a certain period of time. time (T0); or (b) the total number of ACK / NACK transmitted by the UE in response to streaming downlink data to the UE from its serving cell if all data blocks are received.

Therefore, the performance of the serving cell (for example, the performance of the PCelda, SCelda or PSCelda) can be expressed in terms of the probability of ACK / NACK or in terms of the total number of ACK / NACK lost in response to receiving downlink data. The outage in the PCelda can be called a "PCelda outage in terms of the number of ACK / NACKs lost". The outage on any SCelda can be called a "SCelda outage in terms of the number of ACK / NACKs lost".

The system information (SI) can include the information in one or more of: MIB, SIB 1, SIB2, SIB3, SIB-NB, SIB-BR, etc.

In specific embodiments, a wireless network can be configured with different TTI patterns. For example, a UE can be configured with a serving cell (eg, a PCcell), also called a single carrier operation. A UE herein is capable of at least two different TTIs (eg, 1ms TTI and 2-OS TTI, etc.). The UE may be configured with any of the plurality of TTIs supported by the UE in a time resource in the serving cell. The UE may further be able to support the operation whereby the TTI changes over time in the serving cell. The UE may further be able to support the operation using different TTIs in the uplink and downlink of the serving cell. An example of some basic scenarios is described in Table 1 below.

Table 1: Example of basic scenarios for the TTI pattern

Specific embodiments are described with reference to FIGURES 7-13B of the drawings, with like numbers being used for like and corresponding parts of the various drawings. LTE is used throughout this description as an example of a mobile system, but the ideas presented in this document can be applied to other wireless communication systems as well.

FIGURE 7 is a block diagram illustrating an example of a wireless network, according to a specific embodiment. The wireless network 100 includes one or more wireless devices 110 (such as mobile phones, smartphones, laptops, tablets, MTC devices, or any other device that can provide wireless communication) and a plurality of network nodes 120 (such as base stations or eNodeB). Network node 120 serves coverage area 115 (also referred to as cell 115).

In general, wireless devices 110 that are within coverage of radio network node 120 (eg, within cell 115 served by network node 120) communicate with radio network node 120 by transmitting and receiving. wireless signals. For example, wireless devices 110 and radio network node 120 can communicate wireless signals 130 that contain voice traffic, data traffic (eg, video broadcast), and / or control signals. A network node 120 that communicates voice traffic, data traffic, and / or control signals to the wireless device 110 may be referred to as a serving network node 120 for the wireless device 110. Wireless signals 130 may include both downlink transmissions (from radio network node 120 to wireless devices 110) and uplink transmissions (from wireless devices 110 to radio network node 120).

In some embodiments, wireless device 110 may be referred to by the non-limiting term "UE". A UE can include any type of wireless device capable of communicating with a network node or another UE via radio signals. A UE may comprise a radio communication device, a target device, a device-to-device (D2D) UE, a machine-to-machine UE or a UE capable of machine-to-machine communication (M2M), a sensor equipped with UE , an iPAD, a tablet, mobile terminals, a smartphone, an integrated laptop computer (LEE), a laptop-mounted computer (LME), USB devices, a customer premises computer (CPE), etc.

In some embodiments, the network node 120 may include any type of network node, such as a base station, a radio base station, a base transceiver station, a base station controller, a network controller, an evolved Node B ( eNB), a gNB, a Node B, a multi-RAT base station, a Multicast / Multicast Coordination Entity (MCE), a relay node, an access point, a radio access point, a Remote Radio Head (RRH) of Remote Radio Unit (RRU), a core network node (for example, an MME, a SON node, a coordination node, etc.), or even an external node (for example, a node of third parties, a node outside the current network), etc.

The wireless network 100 may include TTIs of various lengths (eg, 1 ms TTI, or short TTI of 2nd, 4th, 7th, etc., or any combination). In particular embodiments, the wireless network 100 may include different TTIs on the downlink and on the uplink.

Wireless device 110 can acquire a system information (SI) from another cell 115. Wireless device 100 can acquire SI from cell 115 in autonomous spaces. Wireless device 110 may transmit a first number of uplink feedback signals in cell 115 in response to receiving downlink data in cell 115 if the UE uses a first TTI in cell 115, and a second number of uplink feedback signals in cell 115 in response to receiving downlink data in cell 115 if the UE uses a second TTI in cell 115. In particular embodiments, wireless device 110 may use the results of the SI acquired from cell 115 to perform one or more operational tasks, such as determining the global cell identity (CGI), transmitting the results to another node, changing the cell, etc. The first TTI has a different length (that is, in terms of number of symbols or time) than the second TTI.

Network node 120 may configure wireless device 110 to acquire system information (SI) from another cell 115 using standalone spaces. Network node 120 may determine a first number of uplink feedback signals that wireless device 110 may transmit in cell 115 in response to receiving downlink data in cell 115 if a first TTI is used by the wireless device 110 in cell 115, or a second number of uplink feedback signals that wireless device 110 can transmit in cell 115 in response to receiving downlink data in cell 115 if a second TTI is used by wireless device 115 in cell 115. Network node 120 may transmit downlink data to wireless device 110. In particular embodiments, the network node 120 may receive uplink feedback signals from the wireless device 110.

Each network node 120 may have a single transmitter or multiple transmitters to transmit wireless signals 130 to the wireless devices 110. In some embodiments, the network node 120 may comprise a multiple input multiple output (MIMO) system. Similarly, each wireless device 110 may have a single receiver or multiple receivers to receive the signals 130 from the network nodes 120.

In the wireless network 100, each node 120 in the radio network can use any suitable radio access technology, such as Long Term Evolution (LTE), LTE-Advanced, NR, UMTS, h SpA, GSM, cdma2000, WiMax , WiFi and / or other suitable radio access technology. The wireless network 100 can include any suitable combination of one or more radio access technologies. By way of example, various embodiments can be described within the context of certain radio access technologies. However, the scope of the description is not limited to the examples and other embodiments could use different radio access technologies.

As described above, embodiments of a wireless network can include one or more wireless devices and one or more different types of radio network nodes capable of communicating with the wireless devices. The network can also include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device (such as a landline phone). A wireless device can include any suitable combination of hardware and / or software. For example, in particular embodiments, a wireless device, such as a wireless device 110, may include the components described below with respect to FIGURE 12A. Similarly, a network node can include any suitable combination of hardware and / or software. For example, in particular embodiments, a network node, such as network node 120, may include the components described below with respect to FIGURE 13A.

Concrete embodiments include methods on a wireless device and on a network node. Example methods are illustrated in FIGURES 8 and 11.

FIGURE 8 is a flow chart of an example method in a wireless device, according to some embodiments. In particular embodiments, one or more steps of the method 800 may be performed by the wireless device 110 of the wireless network 100 described with reference to FIGURE 7.

Method 800 begins at step 812, where a wireless device gets a request to acquire an SI from a second cell (cell2). For example, the wireless device 110 may obtain a request to acquire an SI from a second cell 115 of the network node 120.

In particular embodiments, the wireless device can be requested to acquire the SI of cell2, which can operate on the same carrier as that of the serving cell or on a different carrier than that of the serving cell. In one example, cell2 can operate on a first carrier (F1). In one example, cell2 can operate on a second carrier (F2). Cell2 can be an intrafrequency cell or an interfrequency cell or a cell of another RAT.

In specific embodiments, the wireless device can obtain the request or initiate the acquisition of the SI or a subset of the information contained in the SI of cell2 based on one or more of the following mechanisms: (a) measurement configuration message received from another node (eg, a network node or other wireless device); (b) a message or an indication received from a higher layer in the wireless device indicating the need to acquire the SI of cell2; (c) event, condition or a trigger based on which the wireless device must acquire the SI of cell2 (for example, the wireless device may acquire the SI, if the signal quality of the current serving cell falls below from a threshold, or in another example, the device can acquire the SI if the wireless device acquires the same PCI for two or more cells, including cell2); or (d) a timer in the wireless device indicating that the SI of cell2 needs to be acquired by the wireless device.

A specific example of a received request includes an RRC message that contains one or more of "reportCGI", "report CSG indicator" or "report SI". The terms "SI acquisition" or "SI acquisition" may also be referred to as "SI reading", "SI reading", "identifying or identifying SI", "SI determination", and so on.

In step 814, the wireless device acquires the SI of cell2 for a certain period of time (T0). For example, wireless device 110 may acquire the SI from another cell 115 for a specified period of time (eg, 150 ms).

In particular embodiments, the SI to be acquired by the wireless device may include one or more blocks containing the SI (eg, MIB, SIB1, SIB2, etc.). For example, the wireless device can be requested to acquire the CGI of cell2 that is transmitted in the SI of cell2. In another example, the SI may include a closed subscriber group (CSG) indicator transmitted by cell2.

The wireless device can create autonomous spaces in one or more serving cells to acquire the SI of cell2 for a certain period of time (T0). The parameter, T0, can be predefined, configured by the network node or by another node. For example, the wireless device can create at least 8 spaces each of 5 ms to acquire the MIB and SIB1 of cell2 during T0. The wireless device can also create one or more spaces each of 9 ms to acquire the AFC / AGC of cell2.

The wireless device is served by a first cell (cell1) (eg, the PCcell). Cell1 can operate on F1 or F2. During autonomous spaces, the wireless device: cannot transmit any signal on the uplink of a first cell (cell1) and cannot receive any signal on the downlink of cell1.

In step 816, the wireless device determines a TTI length used for wireless communication with the wireless device in a first cell. For example, wireless device 110 may determine that its serving cell uses a short TTI on the uplink and / or downlink (eg, 2-os, 4-os, 7-os, etc.). Wireless device 110 may receive a TTI configuration from a network node, or wireless device 110 may be pre-configured to support one or more TTI durations. More examples of TTI determination are described below.

In step 818, the wireless device receives the downlink data from the first cell during time T0. For example, network node 120 may continuously transmit data to wireless device 110. Wireless device 110 may receive some or all of the data. For example, wireless device 110 may not receive data while taking measurements in another cell. Thus, wireless device 110 can receive a percentage of the data transmitted by network node 120.

In step 820, the wireless device may transmit a first minimum number (N1) of uplink feedback signals in a first cell (cell1) in response to receiving downlink data in cell1 if the wireless device in the cell1 uses a first TTI (TTI1) during T0, and a second minimum number (N2) of uplink feedback signals in cell1 in response to receiving downlink data in cell1 if a second TTI (TTI2) is used by the wireless device in cell1 during T0. For example, wireless device 110 may receive downlink data from a first cell (cell) during T0 and in response to data received on the cell downlink, the UE may transmit a certain minimum number of uplink feedback signals on the cell1 uplink.

Wireless device 110 may determine a minimum number (N) of uplink feedback signals to be transmitted by wireless device 110 in cell1 in response to receiving data from cell1 during T0. An example of an uplink feedback signal is ACK or NACK transmission. The determination of N by the wireless device 110 may be a consequence of the autonomous space scheduling that is determined by the wireless device 110, rather than the wireless device 110 explicitly performing a calculation to determine N.

For example, the wireless device may obtain the minimum number (N) of uplink feedback signals that the wireless device must transmit in response to at least one continuous transmission of downlink data (e.g., the PDSCH, sPDSCH, NPDSCH , etc.) on the downlink time resources to the wireless device by the network node in cell1 during T0. The minimum number, N, is associated with the TTI used by the wireless device to operate signals in cell1.

The duration of TTI in cell1 affects the number of downlink time resources in which the network node can schedule the wireless device in the downlink of the cell (that is, send the downlink data in cell1) during T0. The TTI used in cell1 also affects the number of uplink time resources in which the wireless device sends the uplink feedback signals in response to the downlink data in cell1 to the network node. Therefore, the value of N increases with a shorter TTI. A higher value of N means that the network will have more opportunities to program the wireless device in cell1 when the wireless device acquires the SI of cell2.

The wireless device can support at least two different TTIs (for example, TTI1 = 1 ms and TTI = 2-OS). In another example, the wireless device may be capable of supporting more than 2 TTIs (eg, TTI1 = 1 ms, TTI2 = 2-OS, TTI3 = 7-OS, etc.).

Continuous transmission of the downlink data herein means that the network node transmits data in all the downlink time resources (for example, in the downlink subframes) in cell1 to the wireless device during the time acquisition of the SI (that is, over time T0). The minimum number, N, may be applicable under or associated with additional conditions or restrictions that may include one or more of: (a) during at least part of T0, the wireless device is not configured with a measurement interval; (b) the wireless device is not configured with a DRX cycle; (c) the wireless device is not working in DRX; (d) the wireless device is configured to receive downlink data from the network node with a predefined number of codewords in a subframe (for example, 1 codeword per subframe) and no MBSFN subframe is configured in the cell service (or PCelda). Examples of subframes that can be configured as MBSFN subframes are subframes # 1, 2, 3, 6, 7 and 8 for FDD and subframes # 3, 4, 7, 8 and 9 for TDD. The MBSFN subframe may contain only PMCH and not PDSCH (or sPDSCH).

The parameter N may further comprise the parameters N1 or N2. The parameter N (or N1 and N2) may further depend on the TDD configurations (ie the uplink / downlink TDD subframe configurations) used in cell1. For example, for the TDD # 0 uplink / downlink configuration and the TDD # 1 uplink / downlink configuration, the values of N can be 18 and 35, respectively. The value of parameters N1 and N2 can be predefined or configured in the wireless device by the network node.

The parameter N = N1, where N1 is the minimum number of uplink feedback signals that the wireless device must transmit in cell1 in response to at least one continuous transmission of downlink data (for example, the PDSCH) to the wireless device by the network node in cell1 during T0 when the wireless device is configured to use a first TTI (TTI1) to operate signals in cell1.

The parameter N = N2, where N2 is the minimum number of uplink feedback signals that the wireless device must transmit in cell1 in response to at least one continuous transmission of downlink data (for example, the PDSCH) to the device wireless by the network node in cell1 during T0 when the wireless device is configured to use a second TTI (TTI2) to operate signals in cell1.

To determine the value of N (N1 or N2), the wireless device may first determine the value of TTI configured for operational signals between the wireless device and cell1. For example, the wireless device determines whether it is configured with TTI1 or TTI2 to operate in cell1.

In one example, the downlink and uplink of cell1 may use the same TTI in the downlink and uplink of cell1, while in another example different TTIs are used in the downlink and uplink of cell1. Therefore, the wireless device can further obtain the TTI of the downlink cell1 as well as the TTI of the uplink cell1.

The wireless device can determine the TTI configured to operate signals in the cell based on one or more of the following mechanisms: (a) the configuration received from the network node, such as a PC cell (for example, the wireless device can determine the TTI used in cell1 receiving control signals on the downlink or receiving an RRC message); (b) a predefined rule, such as predefined information related to the TTI and the carrier frequency (for example, the relationship between the TTI and the frequency band of the carrier frequency used in cell1 (F1)), or apply the same TTI that is used in a reference cell (for example, the PCelda, the PSCelda), or based on the TTI used in the opposite direction of cell1 (for example, assume the same TTI in the uplink and downlink of the cell1, or suppose the uplink of cell1 uses a TTI that is not shorter than the TTI of the downlink of cell1); and (c) autonomous determination (eg, blind detection by the wireless device when attempting to decode the downlink channel of different predefined TTIs).

The wireless device, after determining the TTI used in cell1, determines the value of N (N1 or N2) using a relationship between the T0, the TTI, and the values of N. In another example, the wireless device determines the value of N (N1 or N2) using a relationship between the T0, the TTI, the N values, and the TDD configuration (ie, the uplink / downlink subframe configuration). The value of the parameters N, TTI and T0 and their association can be predefined or configured in the wireless device by the network node. The relationship can be expressed in terms of a function or a correspondence table.

An example of a function that relates N, TTI and T0 is expressed by (1):

N = f (TTI, T0) (1)

Another example of a function that relates the N, TTI, T0 and TDD (Cg) subframe configuration used in cell1 is expressed by (2):

N = f (TTI, T0, Cg) (2)

In an example embodiment, the same TTI is used in the uplink of cell1 and in the downlink of cell1. In a further aspect of some embodiments, different TTIs may be used in the uplink of cell1 and in the downlink of cell1.

In another example, the value of N may further depend on the TTI (TTId) used in the downlink of cell1 and the TTI (TTIu) used in the uplink of cell1. An example of a function that relates N, TTId, TTIu and T0 is expressed by (3):

N = f (TTId, TTIu, T0) (3)

Another example of a function that relates the subframe configuration N, TTId, TTIu, T0 and TDD (Cg) used in cell1 is expressed by (4):

N = f (TTId, TTIu, T0, Cg) (4)

Table 2 shows an example of the correspondence table that relates TTI, N and T0. Table 2 assumes the same TTI is used in cell1. For example, if the wireless device is configured with TTI = 2-OS, then the value of N = X2. But if the wireless device is configured with TTI = 1 ms, then N = X1.

Table 2: Example of value of N for different TTI assuming the same TTI in the uplink and downlink of cell1

An example in Table 3 illustrates a series of uplink feedback signals (e.g. ACK / NACK) sent by the wireless device in cell1 during T0 when the same TTI is used on the uplink and downlink of cell1. The example in Table 3 is for FDD.

Table 3: Example of specific values of N (uplink ACK / NACK) sent by a wireless device in cell1 for different TTIs assuming the same TTI in the uplink and in the downlink of cell1

Therefore, for a first value of TTI that is shorter than a second value of TTI, the first minimum number N1 of feedback signals is greater than the second minimum number N2 of feedback signals. For example, for a first 2 OS TTI, the first minimum N1 number of feedback signals is 465 within a time period. When the wireless device is operating according to a second longer TTI, for example a TTI of 1 ms, i.e. 14 symbols, the second minimum N2 number of feedback signals is less than in the first TTI during the same period time, for example 60 feedback signals. This relationship is applicable to any combination of TTI lengths.

Table 4 shows another example of the correspondence table that relates TTI, N and T0. In Table 4, some embodiments assume that the same TTI is used in cell1, while another set of embodiments assume that different TTIs are used in the uplink and downlink of cell1. For example, if the wireless device is configured with TTI = 2-OS on the downlink and TTI = 1 ms on the uplink, then the value of N = X31. But if the wireless device is configured with TTI = 1 on the downlink and TTI = 2-OS on the uplink of cell1, then the value of N = X41.

Table 4: Example of value of N for the same or different TTIs in the uplink and in the downlink of cell1

An example in Table 5 provides example numbers of uplink feedback signals (e.g. ACK / NACK) sent by the wireless device in cell1 during T0 when different TTIs are used on the uplink and downlink of cell1. The example in Table 5 is for FDD.

Table 5: Example of specific values of N (uplink ACK / NACK) sent by a wireless device in cell1 for different TTIs assuming different TTIs are used in the uplink and in the downlink of cell1

After determining the value of N based on at least the TTI used in cell1, the wireless device can transmit at least the determined number of uplink feedback signals in the uplink of cell1 in response to receiving data. downlink from cell1 during T0. The wireless device also acquires the SI of cell1 during T0.

The wireless device, such as the wireless device 110, may use the results of the acquired SI from cell2 or a subset of the information in the SI of cell2 to perform one or more operational tasks. Examples of operational tasks may include: (a) reporting SI measurement results to another node (eg, a network node or other wireless device); (b) using the SI measurement results for one or more operations (eg, for positioning, power control, link adaptation, cell change as handover); (c) perform the SI measurement meeting a predefined requirement (eg, measurement time (T1), minimum number of uplink feedback signals during T1, number of messages received correctly, etc.); (d) store the results and use them at a later time; and / or (e) cell verification (eg, comparing the PCI and CGI of cell1).

Modifications, additions, or omissions can be made to the method 800 illustrated in FIGURE 8. In addition, one or more steps in the method 800 can be performed in parallel or in any suitable order.

FIGURE 9 illustrates an example of HARQ feedback for the downlink / uplink configuration for 4th / 4th and 7th / 7th, according to some embodiments; and FIGURE 10 illustrates an example of HARQ feedback for the downlink / uplink configuration for 2nd / 2nd and 2nd / 1ms, according to some embodiments.

FIGURE 11 is a flow chart of an example method in a network node, according to some embodiments. In particular embodiments, one or more steps of method 1100 may be performed by components of the wireless network 100 described with reference to FIGURE 7.

Method 1100 begins at step 1162, where a network node configures a wireless device to acquire system information (SI) from a second cell (cell2) during the time period (T0). For example, network node 120 may transmit a request to wireless device 110 to acquire the SI of a second cell (cell2).

In particular embodiments, the network node may first determine the need for the wireless device to acquire the SI of cell2. This can be based on the need to perform one or more tasks (eg cell change, SON, positioning, etc.). The network node can send the request to the wireless device based on any of the examples described with respect to FIGURE 8.

In step 1164, the network node determines a TTI length used for wireless communication with the wireless device in a first cell. For example, network node 120 may determine that wireless device 110 uses a short TTI on the uplink and / or downlink (eg, 2-os, 4-os, 7-os, etc.). More examples of TTI determination are described below and above with respect to FIGURE 8.

In step 1166, the network node transmits a continuous transmission of downlink data to the wireless device during time T0. For example, network node 120 may transmit downlink data to wireless device 110 during T0 in cell1. Network node 120 may transmit data to wireless device 110 on all downlink time resources for at least T0 of cell1. If the wireless device cannot acquire the SI of cell2 during T0, then the network node can schedule link data down on all downlink time resources for a time period greater than T0 (for example, over T1 where T1> T0).

In step 1168, the network node receives a minimum N number of uplink feedback signals during time T0. For example, network node 120 may receive N feedback signals from wireless device 110.

In some embodiments, the network node determines a minimum first number (N1) of uplink feedback signals that the wireless device can transmit in a first cell (cell1) in response to receiving downlink data in cell1 if a first TTI (TTI1) is used by the wireless device in cell1 during T0, or a second minimum number (N2) of uplink feedback signals that the wireless device can transmit in cell1 in response to receiving data from downlink in cell1 if the wireless device uses a second TTI (TTI2) in cell1 during T0.

For example, the network node 120 can determine a certain minimum number (N) of uplink feedback signals that the wireless device 100 can transmit in a first cell (cell1) in response to receiving downlink data in the cell1.

The value of N depends on the value of TTI used by the wireless device in cell1. The value of N may further depend on whether the same TTI is used in the uplink and in the downlink of cell1, or different TTIs are used in the uplink and in the downlink of cell1. The network node determines the value of N based on at least the TTI used in cell1 (or the TTIs used in the uplink and downlink of cell1) based on the same principles, functions or mapping tables as described with respect to FIGURE 8.

The network node can receive N1 uplink feedback signals from the wireless device in cell1 in response to the transmission of downlink data in cell1 if the wireless device in cell1 uses the TTI1 during T0, or feedback N2 uplink from the wireless device in cell1 in response to the transmission of the downlink data in cell1 if the wireless device in cell1 uses TTI2 during T0. For example, network node 120 may receive a number of uplink feedback signals in response to transmission of downlink data to wireless device 110 in cell1 for at least T0.

The network node expects to receive at least N1 uplink feedback signals from the wireless device if the wireless device can acquire the SI at T0 if the wireless device uses the TTI1 to operate signals in cell1. The network node expects to receive at least N2 uplink feedback signals from the wireless device if the wireless device can acquire the SI at T0 if the wireless device uses the TTI2 to operate signals in cell1. The number of uplink feedback signals received by the network node from the wireless device in response to the transmission of downlink data to the wireless device in cell1 for at least T0 may further depend on whether the same or different are used. TTI on the uplink and downlink of cell1 during T0.

The network node, such as the network node 120, may use the results of the number of uplink feedback signals received from the wireless device in cell1 and / or the results of the acquired SI from cell1 to perform one or more. more operational tasks. Examples of operational tasks may include: (a) using the SI measurement results for one or more operations (eg, for positioning, power control, link adaptation, cell change as handover, etc.); (b) store the results and use them at a later time; (c) cell verification (eg, comparing the PCI and CGI of cell1); (d) adapting or improving data scheduling to the wireless device on the uplink and / or the downlink of the serving cell of the wireless device; (d) adapting the measurement configuration and transmitting the adapted measurement configuration to the wireless device; and / or (e) reconfigure the cell parameters (eg, transmit power, antenna transmission mode, etc.).

Modifications, additions, or omissions can be made to method 1100 illustrated in FIGURE 11. Additionally, one or more steps in method 1100 can be performed in parallel or in any suitable order.

FIGURE 12A is a block diagram illustrating an example embodiment of a wireless device. The wireless device is an example of the wireless devices 110 illustrated in FIGURE 7. Concrete examples include a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a laptop (eg, a laptop, a tablet) , a sensor, a modem, a machine-type device (MTC) / machine-to-machine device (M2M), laptop embedded kit (LEE), laptop-mounted kit (LME), USB devices, a device-capable device a device, an NB-IoT device, or any other device that can provide wireless communication. The wireless device includes transceiver 1210, processing circuitry 1220, memory 1230, and power supply 1240. In some embodiments, the transceiver 1210 facilitates the transmission of wireless signals and the reception of wireless signals from the wireless network node 120 (for example, through an antenna), the processing circuitry 1220 executes instructions to provide some or all the functions described herein, such as the provides the wireless device, and memory 1230 stores instructions executed by processing circuitry 1220. Power supply 1240 supplies electrical power to one or more of the components of wireless device 110, such as transceiver 1210, processing circuitry 1220, and / or memory 1230.

According to some embodiments, the wireless device 110 is capable of obtaining a request to acquire the SI of a cell; obtain the SI of the cell during a period of time (T0); and determining a TTI length used for wireless communication in your serving cell (s). When the determined TTI length equals a first TTI value (TTI1), the wireless device transmits a first minimum number (N1) of uplink feedback signals on the uplink of the serving cell during T0. When the determined TTI length equals a second TTI value (TTI2), the wireless device transmits a second minimum number (N2) of uplink feedback signals on the uplink of the serving cell during T0.

Processing circuitry 1220 includes any suitable combination of hardware and software implemented in one or more integrated circuits or modules to execute instructions and manipulate data to perform some or all of the described functions of the wireless device. In some embodiments, the processing circuitry 1220 may include, for example, one or more computers, one or more programmable logic devices, one or more central processing units (CPUs), one or more microprocessors, one or more applications, and / or another. logic, and / or any suitable combination of the above. Processing circuitry 1220 may include analog and / or digital circuitry configured to perform some or all of the described functions of wireless device 110. For example, processing circuitry 1220 can include resistors, capacitors, inductors, transistors, diodes, and / or any other suitable circuit components.

Memory 1230 is generally operative to store computer executable code and data. Examples of 1230 memory include computer memory (for example, random access memory (RAM) or read-only memory (ROM)), mass storage media (for example, a hard drive), removable storage media (for example , a Compact Disc (CD) or a Digital Video Disc (DVD)), and / or any other volatile or non-volatile, non-transient, computer-readable and / or computer-executable memory device that stores information.

The power supply 1240 can be generally operated to supply electrical power to the components of the wireless device 110. The power supply 1240 may include any suitable type of battery, such as lithium ion, lithium-air, lithium polymer, nickel cadmium, nickel metal hydride, or any other type of battery suitable for supplying power to a Wireless device.

In particular embodiments, processing circuitry 1220 in communication with transceiver 1210 acquires system information in self-contained space and transmits measurement results to network node 120, according to any of the embodiments described herein. Other embodiments of the wireless device may include additional components (in addition to those shown in FIGURE 12A) responsible for providing certain aspects of the functionality of the wireless device, including any of the functions described above and / or any additional functionality (including any functionality). needed to support the solution described above).

FIGURE 12B is a block diagram illustrating example components of a wireless device 110. The components may include the obtaining module 1250, the determining module 1252, the receiving module 1254, and the transmitting module 1256.

The obtain module 1250 may perform the obtain functions of the wireless device 110. For example, the obtain module 1250 may perform the obtain functions of steps 812 and 814 in FIGURE 8. In certain embodiments, the obtain module 1250 may include or be included in the processing circuitry 1220. In particular embodiments, the obtaining module 1250 may communicate with the determining module 1252, the receiving module 1254, and the transmitting module 1254.

The determination module 1252 may perform the determination functions of the wireless device 110. For example, the determination module 1252 may perform the determination functions of step 816 in FIGURE 8. In certain embodiments, the determination module 1252 may include or be included in the processing circuitry 1220. In particular embodiments, the determining module 1252 may communicate with the obtaining module 1250, the receiving module 1254, and the transmitting module 1254.

The receiving module 1254 may perform the receiving functions of the wireless device 110. For example, the receiving module 1254 may perform the receiving functions of step 818 in FIGURE 8. In certain embodiments, the transmitting module 1254 may include or be included in the processing circuitry 1220. In particular embodiments, the transmission module 1254 may communicate with the acquisition module 1250 and the acquisition module 1252.

The transmitting module 1256 may perform the transmitting functions of the wireless device 110. For example, the transmit module 1256 may perform the transmit functions of step 820 in FIGURE 8. In certain embodiments, the transmit module 1256 may include or be included in the circuitry 1220 of prosecution. In particular embodiments, the transmitting module 1256 may communicate with the obtaining module 1250, the determining module 1252, and the receiving module 1254.

FIGURE 13A is a block diagram illustrating an example embodiment of a network node. The network node 120 may be an eNodeB, a nodeB, a base station, a wireless access point (e.g., a Wi-Fi access point), a low-power node, a base transceiver station (BTS), a transmitting point or node, a remote RF unit (RRU), a remote radio head (RRH) or other radio access node. Network node 120 includes at least one transceiver 1310, processing circuitry 1320, at least one memory 1330, and at least one network interface 1340. Transceiver 1310 facilitates the transmission of wireless signals and the reception of wireless signals from a wireless device, such as wireless devices 110 (eg, through an antenna); processing circuitry 1320 executes instructions to provide some or all of the functionality described above as provided by a network node 120; memory 1330 stores instructions executed by processing circuitry 1320; and the network interface 1340 communicates signals to components of the backend network, such as a gateway, switch, router, Internet, Public Switched Telephone Network (PSTN), controller, and / or other network nodes 120. The processing circuitry 1320 and memory 1330 may be of the same types as described with respect to the processing circuitry 1220 and memory 1230 of FIGURE 12A above.

The network node is capable of configuring a wireless device to acquire the SI of a cell during a period of time (T0); determining a TTI length used for wireless communication with the wireless device in a serving cell; and transmitting a continuous allocation of downlink data to the wireless device during time T0. When the determined TTI length equals a first TTI value (TTI1), the network node is capable of receiving a first minimum number (N1) of uplink feedback signals from the wireless device during T0. When the determined TTI length equals a second TTI value (TTI2), the network node is capable of receiving a second minimum number (N2) of uplink feedback signals from the wireless device during T0.

In some embodiments, the network interface 1340 is communicatively coupled to the processing circuitry 1320 and refers to any suitable device that can be operated to receive input for the network node 120, send output from the network node 120, perform the proper processing of input or output or both, communicate with other devices, or any combination of the above. The network interface 1340 includes appropriate hardware (for example, a port, a modem, a network interface card, etc.) and software, including data processing and protocol conversion capabilities, to communicate over a network . In particular embodiments, processing circuitry 1320 in communication with transceiver 1310 transmits downlink data to wireless device 110 and receives uplink feedback signals from wireless device 110.

Other embodiments of the network node 120 include additional components (in addition to those shown in FIGURE 13A) responsible for providing certain aspects of the functionality of the network node, including any of the functions described above and / or any additional functionality (including any functionality required to support the solution described above). The various different types of radio network nodes may include components that have the same physical hardware but configured (eg, programmatically) to support different radio access technologies, or they may represent partially or completely different physical components.

FIGURE 13B is a block diagram illustrating example components of a network node 120. The components may include the configuration module 1350, the determining module 1352, the transmitting module 1354, and the receiving module 1356.

The configuration module 1350 can perform the configuration functions of the network node 120. For example, the configuration module 1350 may perform the configuration functions of step 1162 in FIGURE 11. In certain embodiments, the configuration module 1350 may include or be included in the processing circuitry 1320. In particular embodiments, the configuration module 1350 may communicate with the determining module 1352, the transmitting module 1354, and the receiving module 1356.

The determination module 1352 may perform the determination functions of the network node 120. For example, the determination module 1352 may perform the determination functions of step 1164 in FIGURE 11. In certain embodiments, the determination module 1352 may include or be included in the processing circuitry 1320. In particular embodiments, the determining module 1352 may communicate with the configuration module 1350, the transmitting module 1354, and the receiving module 1356.

The transmission module 1354 can perform the transmission functions of the network node 120. For example, the transmit module 1354 may perform the transmit functions of step 1166 in FIGURE 11. In certain embodiments, the transmit module 1354 may include or be included in the processing circuitry 1320. In particular embodiments, the transmitting module 1354 may communicate with the configuration module 1250, the determining module 1352, and the receiving module 1356.

The receiving module 1356 may perform the receiving functions of the network node 120. For example, the receiving module 1356 may perform the receiving functions of step 1168 in FIGURE 11. In certain embodiments, the receiving module 1356 may include or be included in processing circuitry 1320. In particular embodiments, the receiving module 1356 may communicate with the configuration module 1350, the determining module 1352, and the transmitting module 1354.

Some embodiments of the description may provide one or more technical advantages. For example, a particular advantage of some embodiments is that the behavior of the UE with respect to the performance of the serving cell when acquiring the SI of a target cell is well defined. Another advantage is that the performance of scheduling the data to the UE in the serving cell is improved. This is because scheduling grants can be used more efficiently. Furthermore, the performance of the SI acquisition can at least be maintained or even improved, even if a UE uses different TTIs in the uplink and the downlink of its serving cell. Some embodiments may benefit from some, none, or all of these advantages. One skilled in the art can easily determine other technical advantages.

Although this description has been described in terms of certain embodiments, alterations and permutations of the embodiments will be apparent to those skilled in the art. Although some embodiments have been described with reference to certain radio access technologies, any suitable radio access technology (RAT) or combination of radio access technologies can be used, such as Long Term Evolution (LTE), LTE- Advanced, NR, UMTS, HSPA. , GSM, cdma2000, WiMax, WiFi, etc. Accordingly, the above description of the embodiments does not limit this description. Other changes, substitutions and alterations are possible without departing from the scope of this description.

In some respects, the examples can be defined without one or more of: obtaining a request to acquire the SI of the second cell; obtain the Si of the second cell during a period of time (T0); and / or determining a TTI length used in the first cell.

The following examples are examples of how certain aspects of the embodiments described herein could be implemented within the framework of a specific communication standard. In particular, the following examples provide a non-limiting example of how the embodiments described herein could be implemented within the framework of a 3GPP RAN standard. The changes described by the examples are simply intended to illustrate how certain aspects of the embodiments could be implemented in a particular standard. However, the embodiments could also be implemented in other suitable ways, both in the 3GPP Specification and in other specifications or standards.

The following sections can be modified in TS 3GPP 36.133 v14.1.0.

E-UTRAN FDD intrafrequency measurements with autonomous spaces Identification of a new E-UTRA cell CGI with autonomous spaces

An explicit neighbor list is not provided to the UE to identify a new CGI of the E-UTRA cell. The UE will identify and notify the CGI when requested by the network for the purpose of 'reportingCGI'. The UE can create autonomous spaces in downlink reception and uplink transmission to receive MIB and SIB1 messages according to clause 5.5.3.1 of TS 36.331. Note that a UE is not required to use a standalone space if if-RequestForHO is set to false. If autonomous spaces are used for measurement for the purpose of 'reporting CGI', regardless of whether DRX or eDRX_CON is used or not, or whether the SCelda or SCeldas are configured or not, the UE will be able to identify a new CGI of Cell E-UTRA within:

T

ldent¡r_CGI, intra _ T 1 l ântif_CGI_tiasÍH). intra

where ^{identif _CGI_basic, intra} = 150 ms. This is the time period used in the above equation where the maximum time allowed for the UE to identify a new CGI of an E-UTRA cell is defined, provided that the UE has already identified the E-UTRA cell.

A cell will be considered identifiable if the following conditions are met: (a) the RSRP-related side conditions indicated in Clause 9.1 are met for a corresponding Band; and (b) SCH_RP and SCH És / Iot according to Annex B.2.2 for a corresponding Band

The MIB of an E-UTRA cell whose CGI is identified will be considered decodable by the UE as long as the PBCH demodulation requirements are met.

The requirement to identify a new CGI of an E-UTRA cell within T ^{identif_CGi_basico, intra} is applicable when DRX is not used, as well as when using any of the DRX or eDRX_CON cycles specified in TS 36.331.

Within the time, T ^{Identif_CGI, intra} ms, over which the UE identifies the new CGI of the E-UTRA cell, the UE will transmit at least N ^min of ACK / NACK in the PCelda or each of the SCeldas activated as specified in Table 6, provided one or more of the following is true: (a) there is a continuous allocation of link data falling; (b) no DRX cycle or eDRX_CON is used; (c) no measurement spaces are configured; (d) only one codeword is transmitted in each subframe; and (e) no MBSFN subframes are configured in the PCelda or in each of the activated SCeldas.

Table 6: Requirement on the minimum number of ACK / NACK to transmit during

E-UTRAN FDD-FDD Interfrequency measurements with autonomous spaces Identification of a new CGI of the E-UTRA FDD cubicle with autonomous spaces

An explicit neighbor list is not provided to the UE to identify a new CGI of the E-UTRA cell. The UE will identify and notify the CGI when requested by the network for the purpose of 'reportingCGI'. The UE can create autonomous spaces in both downlink reception and uplink transmission to receive MIB and SIB1 messages according to clause 5.5.3.1 of TS 36.331. Note that a UE is not required to use a standalone space if if-RequestForHO is set to false. If autonomous spaces are used for the measurement for the purpose of 'reporting CGI', regardless of whether DRX or eDRX_CON is used or not, or whether the SCelda or SCeldas are configured or not, the UE will be able to identify a new CGI of Cell E- UTRA within:

T

ldent¡r_CGI, intra _ T 1 l ântif_CGI_tiasÍH). intra

where T ^{identif_CGI_basic, inter} = 150 ms. This is the time period used in the above equation where the maximum time allowed for the UE to identify a new CGI of the E-UTRA cell is defined, provided that the E-UTRA cell has already been identified by the UE.

A cell will be considered identifiable if the following conditions are met: (a) the RSRP-related side conditions indicated in Clause 9.1 are met for a corresponding Band; and (b) SCH_RP | dBm and SCH És / Iot according to Annex B.2.3 for a corresponding Band.

The MIB of an E-UTRA cell whose CGI is identified will be considered decodable by the UE as long as the PBCH demodulation requirements are met.

The requirement to identify a new CGI of an E-UTRA cell within T ^{identif_CGI_basic, inter} is applicable when DRX is not used, as well as when using any of the DRX or eDRX_CON cycles specified in TS 36.331.

Within the time, T ^{identif_CGI_basic, intra} ms, on which the UE identifies the new CGI of the E-UTRA cell, the UE will transmit at least N ^min ACK / NACK in the PCelda or in each SCelda or SCeldas activated as specified in Table 7, provided one or more of the following are true: (a) there is a continuous allocation of DL data; (b) no DRX cycle or eDRX_CON is used; (c) no measurement spaces are configured; (d) only one codeword is transmitted in each subframe; and (e) no MBSFN subframes are configured in the PCelda or in each of the activated SCeldas.

Table 7: Requirement on the minimum number of ACK / NACK to transmit during

Abbreviations:

3GPP 3 Third Generation Partnership Project

BLER Block error rate

CGI Global Cell Identifier

CFI Control Format Indicator

CP Cyclic Prefix

CRS Common Reference Signal

DFT Discrete Fourier Transform

DMRS Demodulation Reference Signal

eMTC Enhanced MTC

eNB Node B Evolved

eNodeB Evolved Node B

E-UTRA UTRA Enhanced

FDD Frequency Division Duplexing

HARQ Hybrid Automatic Replay Request

LTE Long-Term Evolution

Master Information Block MIB

MTC Machine Type Communication

OFDM Orthogonal Frequency

PCFICH Physical CFI Channel

PDCCH Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PHICH Physical HARQ Indication Channel

PRB Physical Resources Block

PSS Primary Synchronization Source

RAT Radio Access Technology

RF Radio Frequency

RRC Radio Resource Control

SC-FDMA Single Carrier Frequency Division Multiplexing SFN Single Frequency Network / System Frame Number SI System Information

SIB System Information Block

SSS Secondary Synchronization Source

TDD Time Division Duplexing

TTI Transmission Time Interval

UE User Equipment

UMTS Universal Mobile Telecommunications System

UTRA Access by UMTS Terrestrial Radio

Claims (17)

1. A method for use in a wireless device in communication with a first cell to acquire system information, SI, from a second cell, the first cell can be operated to use two or more transmission time slots, TTI, comprising the method: obtaining (812) a request to acquire the SI of the second cell; obtaining (814) the SI of the second cell for a period of time, T0; determining (816) a TTI length used for wireless communication with the wireless device in the first cell; in response to receiving (818) downlink data from the first cell during time T0: when the determined TTI length equals a first TTI value, TTI1, transmit (820) a first minimum number, N1, of signals uplink feedback on the uplink of the first cell during T0; and when the determined TTI length equals a second TTI value, TTI2, transmitting (820) a second minimum number, N2, of uplink feedback signals in the uplink of the first cell during T0; where TTI1 is a shorter duration than TTI2 and N1 is greater than N2. The method of claim 1, wherein determining (816) the TTI length comprises determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. The method of any of claims 1-2, wherein obtaining (814) the SI of the second cell includes measuring signals in a series of measurement spaces, and the method further comprises: when the wireless device is unable to transmit the N1 or N2 uplink feedback signals during T0, reduce the number of measurement spaces or increase T0, or, where the obtaining (814) of the SI from the second cell includes the signals measurement in a number of measurement spaces, and the method further comprises: when the wireless device is unable to transmit the N1 or N2 uplink feedback signals during T0, reduce the number of measurement spaces or increase T0 and where the measurement spaces comprise autonomous spaces created by the wireless device in at least the first cell during time T0. The method of claim 1, wherein TTI1 is less than 1 ms and N1 is greater than 60, and / or where N1 and N2 depend on a time division duplexing uplink / downlink subframe configuration. (TDD) of the first cell. The method of any of claims 1 to 4, wherein the uplink feedback signals include hybrid auto-repeat request signals, HARQ, acknowledge, ACK, and negative acknowledge, NACK. 6. A wireless device (110) in communication with a first cell (115) to acquire system information, SI, from a second cell (115), the first cell can be operated to use two or more transmission time slots, TTI, the wireless device comprising processing circuitry (1120) that can be operated to: obtain a request to acquire the SI of the second cell; obtain the SI of the second cell for a period of time, T0; determining a TTI length used for wireless communication with the wireless device in the first cell; in response to receiving downlink data from the first cell during time T0: when the determined TTI length equals a first TTI value, TTI1, transmitting a first minimum number, N1, of uplink feedback signals on the uplink of the first cell during T0; and when the determined TTI length equals a second TTI value, TTI2, transmitting a second minimum number, N2, of uplink feedback signals on the uplink of the first cell during T0; where TTI1 is a shorter duration than TTI2 and N1 is greater than N2. The wireless device of claim 6, wherein the processing circuitry can be operated to determine the TTI length by determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. first cell. The wireless device of any of claims 6 to 7, wherein the processing circuitry can be operated to obtain the SI of the second cell by measuring signals in a series of measurement spaces, and the processing circuitry can be operated also for: when the wireless device cannot transmit the N1 or N2 uplink feedback signals during T0, reduce the number of measurement spaces or increase T0, or, where the processing circuitry can be operated to obtain the SI of the second cell measuring signals in a number of measurement spaces, and the processing circuitry can be further operated to: when the wireless device is unable to transmit the N1 or N2 uplink feedback signals during T0, reduce the number of measurement spaces or increase T0 and where the measurement spaces comprise autonomous spaces created by the wireless device in at least the first cell during time T0. The wireless device according to claim 6, wherein TTI1 is less than 1 ms and N1 is greater than 60, and / or, wherein N1 and N2 depend on a duplexing uplink / downlink subframe configuration by time division, TDD, of the first cell. The wireless device according to any one of claims 6 to 9, wherein the uplink feedback signals include hybrid auto-repeat request signals, HARQ, acknowledge, ACK, and negative acknowledge, NACK. 11. A method to use in a network node of a first cell to configure a wireless device to acquire system information, SI, from a second cell, the first cell can be operated to use two or more transmission time slots, TTI, comprising the method: configuring (1162) the wireless device to acquire the SI of the second cell for a period of time, T0; determining (1164) a TTI length used for wireless communication with the wireless device in the first cell; transmitting (1166) a continuous allocation of downlink data to the wireless device during time T0; when the determined TTI length equals a first TTI value, TTI1, receiving (1168) a first minimum number, N1, of uplink feedback signals from the wireless device during T0; and when the determined TTI length equals a second TTI value, TTI2, receiving (1168) a second minimum number, N2 of uplink feedback signals from the wireless device during T0; where TTI1 is a shorter duration than TTI2 and N1 is greater than N2. The method of claim 11, wherein determining (1164) the TTI length comprises determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell, and / or It further understands that when the network node does not receive the N1 or N2 uplink feedback signals during T0, increasing T0. 13. The method of claim 11, wherein TTI1 is less than 1 ms and N1 is greater than 60, and / or, wherein N1 and N2 depend on a time division duplexing uplink / downlink, TDD, subframe configuration of the first cell. 14. A network node (120) of a first cell (115) capable of configuring a wireless device (110) to acquire system information, SI, from a second cell (115), the first cell can be operated to use two or more transmission time slots, TTI, the network node comprising processing circuitry (1220) that can be operated to: configuring the wireless device to acquire the SI of the second cell for a period of time, T0; determining a TTI length used for wireless communication with the wireless device in the first cell; transmitting a continuous allocation of downlink data to the wireless device during time T0; when the determined TTI length equals a first TTI value, TTI1, receiving a first minimum number, N1, of uplink feedback signals from the wireless device during T0; and when the determined TTI length equals a second TTI value, TTI2, receiving a second minimum number, N2 of uplink feedback signals from the wireless device during T0; where TTI1 is a shorter duration than TTI2 and N1 is greater than N2. The network node of claim 14, wherein the processor is operable to determine the TTI length by determining an uplink TTI length used in the first cell and a downlink TTI length used in the first cell. , and / or the processor can be further operated to, when the network node does not receive the N1 or N2 uplink feedback signals during T0, increase T0. 16. The network node of claim 14, wherein TTI1 is less than 1 ms and N1 is greater than 60, and / or, wherein N1 and N2 depend on a time division duplexing uplink / downlink TDD subframe configuration of the first cell. 17. The network node of any of claims 14 to 16, wherein the uplink feedback signals include hybrid auto-repeat request, HARQ, acknowledge, ACK, and negative acknowledge, NACK.